Speed change gear system

ABSTRACT

A speed change gear system for providing at least four forward drive speed ranges and one reverse drive speed range includes planetary gear sets of the single-pinion type and simple planetary gear sets of the double-pinion type as well as a plurality of clutches and brakes. As a result of the coupling and uncoupling of the clutches and brakes, the movable elements of the gear sets are suitably coupled so as to attain the various speed ranges.

BACKGROUND OF THE INVENTION

1. Field of the Invention:

The present invention relates generally to speed change gear systems and more particularly to a speed change gear system which is adapted for application with fluid couplings utilized within motor vehicles, especially automobiles.

2. Description of the Prior Art:

It is preferable to utilize at least four gear sets within the speed change gear system of large automotive vehicles, such as for example, trucks and buses, and in order to attain a speed change mechanism having more than four speed shifts, three, four or even more sets of simple, single-pinion or double-pinion type planetary gear sets have been heretofore combined. While the combination of these gears may be widely varied, it is preferable however that the following conditions be attained:

1. The outlet shaft should be coupled to the same elements within each speed range.

2. In order to reduce the circumferential speed of the bearing of each element of the planetary gear set, the number of its revolutions should be small.

3. The tooth load, that is, the tangential force of each element should be small so as to maintain the strength of the gear teeth.

4. The gear set should always attain meshing conditions for the number of teeth required. For example, the sun gear, whose diameter is to be minimized, as well as each planetary pinion gear, should have the necessary number of teeth.

5. Within the planetary gear set, the coupling relationship among the elements should be simple and the distance from each other should be small.

6. During speed shifts, wherein frictional coupling means are utilized during forward drive, such speed shifts should be available through one coupling means alone.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a speed change gear system which provides at least four speed ranges for forward drive and one speed range for reverse drive by the use of planetary gear sets of the single-pinion type and simple planetary gear sets of the double-pinion type.

BRIEF DESCRIPTION OF THE DRAWINGS

Various other objects, features and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood from the following detailed description when considered in conjunction with the accompanying drawings, in which like reference characters designate like or corresponding parts throughout the several views, and wherein:

FIG. 1A is a schematic view of one embodiment of a speed change gear system constructed in accordance with the present invention and disclosing its cooperative parts;

FIG. 2A is a schematic view similar to that of FIG. 1 showing however another embodiment of the present invention;

FIG. 3A is a schematic view similar to that of FIG. 1 showing however yet another embodiment of the present invention;

FIG. 4A is a schematic view similar to that of FIG. 1 showing however still another embodiment of the present invention;

FIG. 5A is a schematic view similar to that of FIG. 1 showing however yet still another embodiment of the present invention;

FIG. 6A is a schematic view similar to that of FIG. 1 showing however a further embodiment of the present invention;

FIG. 7A is a schematic view similar to that of FIG. 1 showing however a yet further embodiment of the present invention;

FIG. 8A is a schematic view similar to that of FIG. 1 showing how a still further embodiment of the present invention; and

FIG. 9A is a schematic view similar to that of FIG. 1 showing however a still yet further embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings and more particularly to FIG. 1A thereof, a first planetary gear set, generally indicated by the reference character X₁, of the double-pinion type, a second planetary gear set, generally indicated by the reference character X₂, of the single-pinion type, and a third planetary gear set, generally indicated by the reference character X₃, also of the single-pinion type are serially interposed between an input shaft and an output shaft. The first planetary gear set X₁ comprises a first sun gear S₁, a first planetary gear P₁ engaged with the first sun gear S₁, a second planetary gear P₂ enmeshed with the first planetary gear P₁, a first ring gear RG₁ engaged with the second planetary gear P₂, and a first carrier C₁ rotatably supporting the first and second planetary gears P₁ and P₂.

The second planetary gear set X₂ similarly comprises a second sun gear S₂ engaged with the first ring gear RG₁, a third planetary gear P₃ enmeshed with the second sun gear S₂, a second ring gear RG₂ engaged with the third planetary gear P₃, and a second carrier C₂ rotatably supporting the third planetary gear P₃ and connected with the first carrier C₁, while the third planetary gear set X₃ likewise comprises a third sun gear S₃, a fourth planetary gear P₄ engaged with the third sun gear S₃, a third ring gear RG₃ enmeshed with the fourth planetary gear P₄, and a third carrier C₃ rotatably supporting the fourth planetary gear P₄ and connected to the second ring gear RG₂ as well as to the output shaft.

A first clutch CL₁ is disposed so as to be capable of simultaneously coupling or uncoupling the first sun gear S₁ and the third sun gear S₃ to or from the input shaft, while a second clutch CL₂ is disposed so as to be capable of simultaneously coupling or uncoupling the first carrier C₁ and the second carrier C₂ to or from the input shaft, and a third clutch CL₃ is similarly disposed so as to be capable of simultaneously coupling or uncoupling the first ring gear RG₁ and the second sun gear S₂ to or from the input shaft. Likewise, a first brake B₁ is disposed so as to be capable of simultaneously locking the first ring gear RG₁ and the second sun gear S₂ to the gear casing, while a second brake B₂ is similarly disposed so as to be capable of simultaneously locking the first carrier C₁ and the second carrier C₂ to the gear casing, and a third brake B₃ is also disposed so as to be capable of locking the third ring gear RG₃ to the gear casing.

The following equation is characteristic of the planetary gear set of the single-pinion type;

    N.sub.RGn  - (1  + I.sub.n) N.sub.cn  + I.sub.n N.sub.sn  = 0

    (n  = 1,2,3, . . .)

while the following equation is characteristic of the planetary gear set of the double-pinion type:

    N.sub.RGn  - (1  - I.sub.n) N.sub.cn  - I.sub.n N.sub.sn  = 0

     (n =  1, 2, 3, . . . )

wherein

N_(RGn) = the number of revolutions of the ring gear;

N_(Cn) = the number of revolutions of the carrier gear;

N_(Sn) = the number of revolutions of the sun gear;and

I_(n) = the radial ratio of the ring gear to the sun gear.

Within this embodiment, the radial ratios within each speed range are I₁ = 0.419, I₂ = 0.500, and I₃ = 0.355. Table 1B shows the relationship between the operation of the clutches CL₁, CL₂, and CL₃ and the brakes B₁, B₂ and B₃ with respect to the reduction gear ratio within each speed range for the five forward speed ranges and the three reverse speed ranges, F_(n) (n = 1, . . . n) designating a forward speed range, such as for example, F₁ designates the first forward speed range, while R_(n) (n = 1, . . . n) designates a reverse speed range, such as for example, R₁ designates the first reverse speed range. Table 1C also shows the relationship between the number of revolutions and the tangential forces of the various elements of the planetary gear sets within each speed range, wherein A designates the speed ranges, B designates the element of the planetary gear sets, N designates the number of revolutions, and W designates the tangential forces. Within Table 1C, like references designate identical or corresponding parts shown within Table 1B and the radial ratios with Table 1C are based upon the assumption that the number of revolutions of the input shaft is 1 while the tangential forces are based upon the assumption that the input shaft torque is exerted upon the ring gear.

In addition, because the reduction gear ratio of the fourth forward speed is 1.00, the number of revolutions of each sun gear, ring gear, and carrier is 1.00 and the number of revolutions of each planetary gear is 0.0., the tangential forces thereof are therefore considerably less than when compared with those within other speed ranges. The input shaft torque is transmitted to all elements as a result of the engagement of one of the clutches within all other speed ranges, however, within the fourth forward speed range, the input shaft torque is distributed by engaging at least two clutches whereby the torque is transmitted to all elements and therefore the tangential forces of such elements are less. Accordingly, the number of revolutions and the tangential forces within the fourth forward speed range having the reduction gear ratio 1.00 are omitted.

                  TABLE 1B                                                         ______________________________________                                                                                    Reduction                           CL1      CL2    CL3    B1   B2    B3  B4   gear ratio                          ______________________________________                                         F1    O                            O         3.82                              F2                  O              O         2.46                              F3           O                     O         1.49                              F4           O      O                        1.00                              F5           O           O                   0.67                              R1    O                       O              -4.77                             R2                  O         O              -2.00                             R3    O                  O                   -0.92                             ______________________________________                                    

                                      TABLE 1C                                     __________________________________________________________________________     B    X1                  X2              X3                                    A    S1  C1  RG1 P1  P2  S2  C2  RG2 P3  S3  C3  RG3 P4                        __________________________________________________________________________        N 1.00                                                                               0.39                                                                               0.65                                                                               -0.93                                                                              0.93                                                                               0.65                                                                               0.39                                                                               0.26                                                                               -0.51                                                                              1.00                                                                               0.26                                                                               0.0 -0.81                     F1 W 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.82                                                                               5.63                                                                               2.82                                                                               2.82                         N 1.55                                                                               0.60                                                                               1.00                                                                               -1.44                                                                              1.44                                                                               1.00                                                                               0.60                                                                               0.41                                                                               -0.79                                                                              1.55                                                                               0.41                                                                               0.0 -1.26                     F2 w 1.24                                                                               2.48                                                                               1.24                                                                               1.24                                                                               1.24                                                                               0.48                                                                               0.96                                                                               0.48                                                                               0.48                                                                               1.46                                                                               2.93                                                                               1.46                                                                               1.46                         N 2.57                                                                               1.00                                                                               1.66                                                                               -2.38                                                                              2.38                                                                               1.66                                                                               1.00                                                                               0.67                                                                               -1.31                                                                              2.57                                                                               0.67                                                                               0.0 -2.08                     F3 w 0.41                                                                               0.83                                                                               0.41                                                                               0.41                                                                               0.41                                                                               0.83                                                                               1.65                                                                               0.83                                                                               0.83                                                                               0.49                                                                               0.98                                                                               0.49                                                                               0.49                         N -1.39                                                                              1.00                                                                               0.0 3.64                                                                               -3.64                                                                              0.0 1.00                                                                               1.50                                                                               2.00                                                                               -1.39                                                                              1.50                                                                               2.52                                                                               3.18                      F4 W 0.0 0.00                                                                               0.0 0.0 0.0 0.67                                                                               1.33                                                                               0.67                                                                               0.67                                                                               0.0 0.0 0.0 0.0                          N 1.00                                                                               0.0 0.42                                                                               -1.52                                                                              1.52                                                                               0.42                                                                               0.00                                                                               -0.21                                                                              -0.84                                                                              1.00                                                                               -0.21                                                                              -0.64                                                                              -1.33                     R1 W 2.39                                                                               4.77                                                                               2.39                                                                               2.39                                                                               2.39                                                                               4.77                                                                               9.55                                                                               4.77                                                                               4.77                                                                               0.0 0.00                                                                               0.0 0.0                          N 2.39                                                                               0.0 1.00                                                                               -3.64                                                                              3.64                                                                               1.00                                                                               0.0 -0.50                                                                              -2.00                                                                              2.39                                                                               -0.50                                                                              -1.52                                                                              -3.18                     R2 W 0.00                                                                               0.00                                                                               0.00                                                                               0.00                                                                               0.00                                                                               2.00                                                                               4.00                                                                               2.00                                                                               2.00                                                                               0.00                                                                               0.00                                                                               0.00                                                                               0.00                         N 1.00                                                                               -0.72                                                                              0.0 -2.62                                                                              2.62                                                                               0.0 -0.72                                                                              -1.08                                                                              -1.44                                                                              1.00                                                                               -1.08                                                                              -1.82                                                                              -2.29                     R3 W 2.39                                                                               4.77                                                                               2.39                                                                               2.39                                                                               2.39                                                                               0.92                                                                               1.85                                                                               0.92                                                                               0.92                                                                               0.00                                                                               0.00                                                                               0.00                                                                               0.00                      __________________________________________________________________________

Referring now to FIG. 2A, a second embodiment of the present invention is disclosed wherein the structure thereof is similar to that of the first embodiment, an additional or fourth planetary gear set, generally indicated by the reference character X₄, of the single-pinion type being disposed behind the third planetary gear set X₃. Set X₄ comprises a fourth sun gear S₄ engaged with the output shaft, a fifth planerary gear P₅ enmeshed with the fourth sun gear S₄, a fourth ring gear RG₄ engaged with the fifth planetary gear P₅ and with the third ring gear RG₃, and a fourth carrier C₄ rotatably supporting the fifth planetary gear P₅. The fourth ring gear RG₄ is locked to the gear casing when the third brake B₃ is actuated, and a fourth brake B₄ is disposed so as to be capable of locking the fourth carrier C₄ to the gear casing.

Within the second embodiment, the radial ratios within each speed range, which are calculated from the formula described in conjunction with the description of the first embodiment are I₁ = 0.419, I₂ = 0.500, I₃ = 0.355, and I₄ = 0.562. Table 2B shows the relationship between the operation of the clutches CL₁, CL₂ and CL₃ and the brakes B₁, B₂, B₃ and B₄ with respect to the reduction gear ratio within each speed range for the eight forward speed ranges and the three reverse speed ranges, while Table 2C shows the relationship between the number of revolutions and the tangential forces of the various elements of the planetary gear sets within each speed range with respect to the reduction gear ratios of the gear sets.

                  TABLE 2B                                                         ______________________________________                                                                                    Reduction                           CL1      CL2    CL3    B1   B2   B3   B4   gear ratio                          ______________________________________                                         F1    O                                 O    5.40                              F2    O                            O         3.82                              F3                  O                   O    3.29                              F4                  O              O         2.46                              F5           O                          O    1.76                              F6           O                     O         1.48                              F7           O      O                        1.00                              F8           O           O                   0.67                              R1    O                       O              -4.77                             R2                  O         O              -2.00                             R3    O                  O                   -0.92                             ______________________________________                                    

                                      TABLE 2C                                     __________________________________________________________________________     B    X1                       X2                                               A    S1   C1   RG1  P1   P2   S2   C2   RG2  P3                                __________________________________________________________________________     F1 N 1.00 0.33 0.61 -1.03                                                                               1.03 0.61 0.33 0.19 -0.56                                W 0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0                               F2 N 1.00 0.39 0.65 -0.93                                                                               0.93 0.65 0.39 0.26 -0.51                                W 0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0                               F3 N 1.64 0.54 1.00 -1.69                                                                               1.69 1.00 0.54 0.30 -0.93                                W 1.24 2.48 1.24 1.24 1.24 0.48 0.96 0.48 0.48                              F4 N 1.55 0.60 1.00 -1.44                                                                               1.44 1.00 0.60 0.41 -0.79                                W 1.24 2.48 1.24 1.24 1.24 0.48 0.96 0.48 0.48                              F5 N 3.06 1.00 1.87 -3.15                                                                               3.15 1.87 1.00 0.57 -1.73                                W 0.41 0.83 0.41 0.41 0.41 0.83 1.65 0.83 0.83                              F6 N 2.57 1.00 1.66 -2.38                                                                               2.38 1.66 1.00 0.67 -1.31                                W 0.41 0.83 0.41 0.41 0.41 0.83 1.65 0.83 0.83                              F7 N -1.39                                                                               1.00 0.0  3.64 -3.64                                                                               0.0  1.00 1.50 2.00                                 W 0.0  0.00 0.0  0.0  0.0  0.67 1.33 0.67 0.67                              R1 N 1.00 0.0  0.42 -1.52                                                                               1.52 0.42 0.00 -0.21                                                                               -0.84                                W 2.39 4.77 2.39 2.39 2.39 4.77 9.55 4.77 4.77                              R2 N 2.39 0.0  1.00 -3.64                                                                               3.64 1.00 0.0  -0.50                                                                               -2.00                                W 0.00 0.00 0.00 0.00 0.00 2.00 4.00 2.00 2.00                              R3 N 1.00 -0.72                                                                               0.0  -2.62                                                                               2.62 0.0  -0.72                                                                               -1.08                                                                               -1.44                                W 2.39 4.77 2.39 2.39 2.39 0.92 1.85 0.92 0.92                              __________________________________________________________________________             B X3                  X4                                               A         S3   C3   RG3  P4   S4   C4   RG4  P5                                __________________________________________________________________________     F1      N 1.00 0.19 -0.10                                                                               -0.90                                                                               0.19 0.00 -0.10                                                                               -0.48                                     W 2.82 5.63 2.82 2.82 2.82 5.63 2.82 2.82                              F2      N 1.00 0.26 0.0  -0.81                                                                               0.26 0.09 0.0  -0.43                                     W 2.82 5.63 2.82 2.82 0.0  0.0  0.0  0.0                               F3      N 1.64 0.30 -0.17                                                                               -1.47                                                                               0.30 0.0  -0.17                                                                               -0.78                                     W 1.46 2.93 1.46 1.46 1.46 2.93 1.46 1.46                              F4      N 1.55 0.41 0.0  -1.26                                                                               0.41 0.15 0.0  -0.67                                     W 1.46 2.93 1.46 1.46 0.0  0.0  0.0  0.0                               F5      N 3.06 0.57 -0.32                                                                               -2.75                                                                               0.57 0.00 -0.32                                                                               -1.46                                     W 0.49 0.98 0.49 0.49 0.49 0.98 0.49 0.49                              F6      N 2.57 0.67 0.0  -2.08                                                                               0.67 0.24 0.0  -1.10                                     W 0.49 0.98 0.49 0.49 0.0  0.0  0.0  0.0                               F7      N -1.39                                                                               1.50 2.52 3.18 1.50 2.16 2.52 1.68                                      W 0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0                               R1      N 1.00 -0.21                                                                               -0.64                                                                               -1.33                                                                               -0.21                                                                               -0.48                                                                               -0.64                                                                               -0.71                                     W 0.0  0.00 0.0  0.0  0.0  0.0  0.0  0.0                               R2      N 2.39 -0.50                                                                               -1.52                                                                               -3.13                                                                               -0.50                                                                               -1.16                                                                               -1.52                                                                               -1.68                                     W 0.00 0.00 0.00 0.00 0.0  0.0  0.0  0.0                               R3      N -1.00                                                                               -1.08                                                                               -1.82                                                                               -2.29                                                                               -1.08                                                                               -1.55                                                                               -1.82                                                                               -1.21                                     W 0.00 0.00 0.00 0.00 0.0  0.0  0.0  0.0                               __________________________________________________________________________

Turning now to FIG. 3A, a third embodiment of the present invention is disclosed wherein the structure thereof is similar to that of the first embodiment, the fourth planetary gear set X₄ of the single pinion type being disposed behind the third planetary gear set X₃ and comprising the fourth sun gear S₄ engaged with the third ring gear RG₃, the fifth planetary gear P₅ enmeshed with the fourth sun gear S₄, the fourth ring gear RG₄ engaged with the fifth planetary gear P₅ and the output shaft, and the fourth carrier C₄ rotatably supporting the fifth planetary gear P₅. The fourth sum gear S₄ is locked to the gear casing when the third brake is actuated and a fourth brake B₄ is disposed so as to be capable of locking the fourth carrier C₄ to the gear casing.

Within the third embodiment, the radial ratios within each speed range which are calculated by the formula described in conjunction with the description of the first embodiment are I₁ = 0.419, I₂ = 0.500, I₃ = 0.355, and I₄ = 0.562. Table 3B shows the relationship between the operation of the clutches CL₁, CL₂ and CL₃ and the brakes B₁, B₂ B₃ and B₄ with respect to the reduction gear ratio within each seed range for the eight forward speed ranges and the three reverse speed ranges, while Table 3C shows the relationship between the number of revolutions and the tangential forces of the various elements of the planetary gear sets within each speed range with respect to the reduction gear ratios of the gear sets.

                  TABLE 3B                                                         ______________________________________                                                                                    Reduction                           CL1      CL2    CL3    B1   B2   B3   B4   gear ratio                          ______________________________________                                         F1    O                                 O    8.83                              F2                  O                   O    5.07                              F3    O                            O         3.82                              F4                  O              O         2.46                              F5           O                          O    2.36                              F6           O                     O         1.49                              F7           O      O                        1.00                              F8           O           O                   0.67                              R1    O                       O              -4.77                             R2                  O         O              -2.00                             R3    O                  O                   -0.92                             R4                                                                             R5                                                                             ______________________________________                                    

                                      TABLE 3C                                     __________________________________________________________________________     B    X1                       X2                                               A    S1   C1   RG1  P1   P2   S2   C2   RG2  P3                                __________________________________________________________________________     F1 N 1.00 0.27 0.57 -1.12                                                                               1.12 0.57 0.27 0.11 -0.61                                W 0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0                               F2 N 1.74 0.46 1.00 -1.95                                                                               1.95 1.00 0.46 0.20 -1.07                                W 1.24 2.48 1.24 1.24 1.24 0.48 0.96 0.48 0.48                              F3 N 1.00 0.39 0.65 -0.93                                                                               0.93 0.65 0.39 0.26 -0.51                                W 0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0                               F4 N 1.55 0.60 1.00 -1.44                                                                               1.44 1.00 0.60 0.41 -0.79                                W 1.24 2.48 1.24 1.24 1.24 0.48 0.96 0.48 0.48                              F5 N 3.75 1.00 2.15 -4.19                                                                               4.19 2.15 1.00 0.42 -2.30                                W 0.41 0.83 0.41 0.41 0.41 0.83 1.65 0.83 0.83                              F6 N 2.57 1.00 1.66 -2.38                                                                               2.38 1.66 1.00 0.67 -1.31                                W 0.41 0.83 0.41 0.41 0.41 0.83 1.65 0.83 0.83                              F8 N -1.39                                                                               1.00 0.0  3.64 - 3.64                                                                              0.0  1.00 1.50 2.00                                 W 0.0  0.00 0.0  0.0  0.0  0.67 1.33 0.67 0.67                              R1 N 1.00 0.0  0.42 -1.52                                                                               1.52 0.42 0.00 -0.21                                                                               -0.84                                W 2.39 4.77 2.39 2.39 2.39 4.77 9.55 4.77 4.77                              R2 N 2.39 0.0  1.00 -3.64                                                                               3.64 1.00 0.0  -0.50                                                                               -2.00                                W 0.00 0.00 0.00 0.00 0.00 2.00 4.00 2.00 2.00                              R3 N 1.00 -0.72                                                                               0.0  -2.62                                                                               2.62 0.0  -0.72                                                                               -1.08                                                                               -1.44                                W 2.39 4.77 2.39 2.39 2.39 0.92 1.85 0.92 0.92                              __________________________________________________________________________             B X3                  X4                                               A         S3   C3   RG3  P4   S4   C4   RG4  P5                                __________________________________________________________________________     F1      N 1.00 0.11 -0.20                                                                               -0.98                                                                               -0.20                                                                               -0.00                                                                               0.11 0.52                                      W 2.82 5.63 2.82 2.82 5.01 10.02                                                                               5.01 5.01                              F2      N 1.74 0.20 -0.35                                                                               -1.70                                                                               -0.35                                                                               0.0  0.20 0.90                                      W 1.46 2.93 1.46 1.46 2.60 5.21 2.60 2.60                              F3      N 1.00 0.26 0.0  -0.81                                                                               0.0  0.17 0.26 0.43                                      W 2.82 5.63 2.82 2.82 0.0  0.0  0.0  0.0                               F4      N 1.55 0.41 0.0  -1.26                                                                               0.0  0.26 0.41 0.67                                      W 1.46 2.93 1.46 1.46 0.0  0.0  0.0  0.0                               F5      N 3.75 0.42 -0.76                                                                               -3.66                                                                               -0.76                                                                               0.00 0.42 1.94                                      W 0.49 0.98 0.49 0.49 0.87 1.74 0.87 0.87                              F6      N 2.57 0.67 0.0  -2.08                                                                               0.0  0.43 0.67 1.10                                      W 0.49 0.98 0.49 0.49 0.0  0.0  0.0  0.0                               F8      N -1.39                                                                               1.50 2.52 3.18 2.52 1.87 1.50 -1.68                                     W 0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0                               R1      N 1.00 -0.21                                                                               -0.64                                                                               -1.33                                                                               -0.64                                                                               -0.36                                                                               -0.21                                                                               0.71                                      W 0.0  0.00 0.0  0.0  0.0  0.0  0.0  0.0                               R2      N 2.39 -0.50                                                                               -1.52                                                                               -3.18                                                                               -1.52                                                                               -0.87                                                                               -0.50                                                                               1.68                                      W 0.00 0.00 0.00 0.00 0.00 0.0  0.0  0.0                               R3      N 1.00 1.08 -1.82                                                                               -2.29                                                                               -1.82                                                                               -1.35                                                                               -1.08                                                                               1.21                                      W 0.00 0.00 0.00 0.00 0.00 0.0  0.0  0.0                               __________________________________________________________________________

Referring now to FIG. 4A, a fourth embodiment of the present invention is disclosed wherein the structure thereof is similar to that of the first embodiment, the fourth planetary gear set X₄ of the single-pinion type being disposed behind the third planetary gear set X₃ and comprising the fourth sun gear S₄, the fifth planetary gear P₅ engaged with the fourth sun gear S₄, the fourth ring gear RG₄ enmeshed with the fifth planetary gear P₅ and connected with the third carrier C₃, and the fourth carrier C₄ rotatably supporting the fifth planetary gear P₅ and connected with the third ring gear RG₃. The fourth carrier C₄ is locked to the gear casing when the third brake B₃ is actuated and a fourth brake B₄ is disposed so as to be capable of locking the fourth sun gear S₄ to the gear casing.

Within the fourth embodiment, the radial ratios within each speed range which are calculated from the formula described in conjunction with the description of the first embodiment are I₁ = 0.419, I₂ = 0.500, I₃ = 0.355, and I₄ = 0.562. Table 4B shows the relationship between the operation of the clutches CL₁, CL₂, and CL₃ and the brakes B₁, B₂, B₃ and B₄ with respect to the reduction gear ratio within each speed range for the eight forward speed ranges and the three reverse speed ranges, while Table 4C shows the relationship between the number of revolutions and the tangential forces of the various elements of the planetary gear sets within each speed range.

                  TABLE 4B                                                         ______________________________________                                                                                    Reduction                           CL1      CL2    CL3    B1   B2   B3   B4   gear ratio                          ______________________________________                                         F1    O                            O         3.82                              F2                  O                   O    2.46                              F3    O                                 O    2.01                              F4                  O                   O    1.53                              F5           O                     O         1.49                              F6           O                          O    1.17                              F7           O      O                        1.00                              F8           O           O                   0.67                              R1    O                       O              -4.77                             R2                  O         O              -2.00                             R3    O                  O                   -0.92                             R4                                                                             R5                                                                             ______________________________________                                    

                                      TABLE 4C                                     __________________________________________________________________________     B    X1                       X2                                               A    S1   C1   RG1  P1   P2   S2   C2   RG2  P3                                __________________________________________________________________________     F1 N 1.00 0.39 0.65 -0.93                                                                               0.93 0.65 0.39 0.26 -0.51                                W 0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0                               F2 N 1.55 0.60 1.00 -1.44                                                                               1.44 1.00 0.60 0.41 -0.79                                W 1.24 2.48 1.24 1.24 1.24 0.48 0.96 0.48 0.48                              F3 N 1.00 0.58 0.76 -0.63                                                                               0.63 0.76 0.58 0.50 -0.35                                W 0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0                               F4 N 1.32 0.77 1.00 -0.84                                                                               0.84 1.00 0.77 0.66 -0.46                                W 1.24 2.48 1.24 1.24 1.24 0.48 0.96 0.48 0.48                              F5 N 2.57 1.00 1.66 -2.38                                                                               2.38 1.66 1.00 0.67 -1.31                                W 0.41 0.83 0.41 0.41 0.41 0.83 1.65 0.83 0.83                              F6 N 1.71 1.00 1.30 -1.09                                                                               1.09 1.30 1.00 0.85 -0.60                                W 0.41 0.83 0.41 0.41 0.41 0.83 1.65 0.83 0.83                              F7 N -1.39                                                                               1.00 0.0  3.64 -3.64                                                                               0.0  1.00 1.50 2.00                                 W 0.0  0.00 0.0  0.0  0.0  0.67 1.33 0.67 0.67                              R1 N 1.00 0.0  0.42 -1.52                                                                               1.52 0.42 0.00 -0.21                                                                               -0.84                                W 2.39 4.77 2.39 2.39 2.39 4.77 9.55 4.77 4.77                              R2 N 2.39 0.0  1.00 -3.64                                                                               3.64 1.00 0.0  -0.50                                                                               -2.00                                W 0.00 0.00 0.00 0.00 0.00 2.00 4.00 2.00 2.00                              R3 N 1.00 -0.72                                                                               0.0  2.62 2.62 0.0  -0.72                                                                               -1.08                                                                               -1.44                                W 2.39 4.77 2.39 2.39 2.39 0.92 1.85 0.92 0.92                              __________________________________________________________________________             B X3                  X4                                               A         S3   C3   RG3  P4   S4   C4   RG4  P5                                __________________________________________________________________________     F1      N 1.00 0.26 0.0  -0.81                                                                               -0.47                                                                               0.0  0.26 1.20                                      W 2.82 5.63 2.82 2.82 0.0  0.00 0.00 0.00                              F2      N 1.55 0.41 0.0  -1.26                                                                               -0.72                                                                               0.0  0.41 1.85                                      W 1.46 2.93 1.46 1.46 0.0  0.00 0.00 0.00                              F3      N 1.00 0.50 0.32 -0.55                                                                               0.0  0.32 0.50 0.82                                      W 2.82 5.63 2.82 2.82 1.80 3.61 1.80 1.80                              F4      N 1.32 0.66 0.42 -0.73                                                                               0.0  0.42 0.66 1.08                                      W 1.46 2.93 1.46 1.46 0.94 1.87 0.94 0.94                              F5      N 2.57 0.67 0.0  -2.08                                                                               -1.20                                                                               0.0  0.67 3.07                                      W 0.49 0.98 0.49 0.49 0.0  0.00 0.0  0.0                               F6      N 1.71 0.85 0.54 -0.95                                                                               0.0  0.54 0.85 1.40                                      W 0.49 0.98 0.49 0.49 0.31 0.62 0.31 0.31                              F7      N -1.39                                                                               1.50 2.52 3.18 4.35 2.52 1.50 -4.68                                     W 0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0                               R1      N 1.00 -0.21                                                                               -0.64                                                                               -1.33                                                                               -1.40                                                                               -0.64                                                                               -0.21                                                                               1.96                                      W 0.00 0.0  0.00 0.00 0.0  0.00 0.0  0.0                               R2      N 2.39 -0.50                                                                               -1.52                                                                               -3.18                                                                               -3.35                                                                               -1.52                                                                               -0.50                                                                               4.68                                      W 0.00 0.00 0.00 0.00 0.0  0.00 0.00 0.00                              R3      N 1.00 -1.08                                                                               -1.82                                                                               -2.29                                                                               -3.14                                                                               -1.82                                                                               -1.08                                                                               3.37                                      W 0.00 0.00 0.00 0.00 0.0  0.00 0.00 0.00                              __________________________________________________________________________

Turning now to FIG. 5A, a fifth embodiment of the present invention is disclosed wherein the structure thereof is similar to that of the first embodiment, the fourth planetary gear set X₄ of the single-pinion type being disposed behind the third planetary gear set X₃ and comprising the fourth sun gear S₄ connected with the output shaft, the fifth planetary gear P₅ engaged with the fourth sun gear S₄, the fourth ring gear RG₄ enmeshed with the fifth planetary gear P₅, and the fourth carrier C₄ rotatably supporting the fifth planetary gear P₅ and connected with the third ring gear RG₃. The fourth carrier C₄ is locked to the gear casing when the third brake is actuated and a fourth brake B₄ is disposed so as to be capable of locking the fourth ring gear RG₄ to the gear casing.

Within the fifth embodiment, the radial ratios within each speed range which are calculated from the formula described in conjunction with the description of the first embodiment are I₁ = 0.419, I₂ = 0.500, I₃ = 0.355, and I₄ = 0.562. Table 5B shows the relationship between the operation of the clutches CL₁, CL₂, and CL₃ and the brakes B₁, B₂, B₃ and B₄ with respect to the reduction gear ratio within each speed range of the eight forward speed ranges and the three reverse speed ranges, while Table 5B shows the relationship between the number of revolutions and the tangential forces of the various elements of the planetary gear sets within each speed range.

                  TABLE 5B                                                         ______________________________________                                                                                    Reduction                           CL1      CL2    CL3    B1   B2   B3   B4   gear ratio                          ______________________________________                                         F1    O                            O         3.82                              F2    O                                 O    2.80                              F3                  O              O         2.46                              F4                  O                   O    1.94                              F5           O                     O         1.49                              F6           O                          O    1.31                              F7           O      O                        1.00                              F8           O           O                   0.67                              R1    O                       O              -4.77                             R2                  O         O              -2.00                             R3    O                  O                   -0.92                             R4                                                                             R5                                                                             ______________________________________                                    

                                      TABLE 5C                                     __________________________________________________________________________     B    X1                       X2                                               A    S1   C1   RG1  P1   P2   S2   C2   RG2  P3                                __________________________________________________________________________     F1 N 1.00 0.39 0.65 -0.93                                                                               0.93 0.65 0.39 0.26 -0.51                                W 0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0                               F2 N 1.00 0.47 0.69 -0.81                                                                               0.81 0.69 0.47 0.36 -0.45                                W 0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0                               F3 N 1.55 0.60 1.00 -1.44                                                                               1.44 1.00 0.60 0.41 -0.79                                W 1.24 2.48 1.24 1.24 1.24 0.48 0.96 0.48 0.48                              F4 N 1.45 0.68 1.00 -1.17                                                                               1.17 1.00 0.68 0.52 -0.65                                W 1.24 2.48 1.24 1.24 1.24 0.48 0.96 0.48 0.48                              F5 N 2.57 1.00 1.66 -2.38                                                                               2.38 1.66 1.00 0.67 -1.31                                W 0.41 0.83 0.41 0.41 0.41 0.83 1.65 0.83 0.83                              F6 N 2.14 1.00 1.48 -1.73                                                                               1.73 1.48 1.00 0.76 -0.95                                W 0.41 0.83 0.41 0.41 0.41 0.83 1.65 0.83 0.83                              F7 N -1.39                                                                               1.00 0.0  3.64 -3.64                                                                               0.0  1.00 1.50 2.00                                 W 0.0  0.00 0.0  0.0  0.0  0.67 1.33 0.67 0.67                              R1 N 1.00 0.0  0.42 -1.52                                                                               1.52 0.42 0.00 -0.21                                                                               -0.84                                W 2.39 4.77 2.39 2.39 2.39 4.77 9.55 4.77 4.77                              R2 N 2.39 0.0  1.00 -3.64                                                                               3.64 1.00 0.0  -0.50                                                                               -2.00                                W 0.00 0.00 0.00 0.00 0.00 2.00 4.00 2.00 2.00                              R3 N 1.00 -0.72                                                                               0.0  -2.62                                                                               2.62 0.0  -0.72                                                                               -1.08                                                                               -1.44                                W 2.39 4.77 2.39 2.39 2.39 0.92 1.85 0.92 0.92                              __________________________________________________________________________             B X3                  X4                                               A         S3   C3   RG3  P4   S4   C4   RG4  P5                                __________________________________________________________________________     F1      N 1.00 0.26 0.0  -0.81                                                                               0.26 0.00 -0.15                                                                               -0.67                                     W 2.82 5.63 2.82 2.82 0.00 0.00 0.00 0.00                              F2      N 1.00 0.36 0.13 -0.71                                                                               0.36 0.13 0.0  -0.59                                     W 2.82 5.63 2.82 2.82 1.80 3.61 1.80 1.80                              F3      N 1.55 0.41 0.0  -1.26                                                                               0.41 0.00 -0.23                                                                               -1.04                                     W 1.46 2.93 1.46 1.46 0.0  0.00 0.0  0.0                               F4      N 1.45 0.52 0.19 -1.02                                                                               0.52 0.19 0.0  -0.85                                     W 1.46 2.93 1.46 1.46 0.94 1.87 0.94 0.94                              F5      N 2.57 0.67 0.0  -2.08                                                                               0.67 0.0  -0.38                                                                               -1.72                                     W 0.49 0.98 0.49 0.49 0.00 0.00 0.00 0.00                              F6      N 2.14 0.76 0.27 -1.51                                                                               0.76 0.27 0.0  -1.25                                     W 0.49 0.98 0.49 0.49 0.31 0.62 0.31 0.31                              F7      N -1.39                                                                               1.50 2.52 3.18 1.50 2.52 3.10 2.63                                      W 0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0                               R1      N 1.00 -0.21                                                                               -0.64                                                                               -1.33                                                                               -0.21                                                                               -0.64                                                                               -0.88                                                                               -1.10                                     W 0.0  0.00 0.0  0.0  0.0  0.0  0.0  0.0                               R2      N 2.39 -0.50                                                                               -1.52                                                                               -3.18                                                                               -0.50                                                                               -1.52                                                                               -2.10                                                                               -2.63                                     W 0.00 0.00 0.00 0.00 0.0  0.00 0.0  0.0                               R3      N 1.00 -1.08                                                                               -1.82                                                                               -2.29                                                                               -1.08                                                                               -1.82                                                                               -2.24                                                                               -1.90                                     W 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00                              __________________________________________________________________________

Referring now to FIG. 6A, a sixth embodiment of the present invention is disclosed wherein the structure thereof is similar to that of the first embodiment, the fourth planetary gear set X₄ of the single-pinion type being disposed behind the third planetary gear set X₃ and comprising the fourth sun gear S₄ connected with the third ring gear RG₃, the fifth planetary gear P₅ engaged with the fourth sun gear S₄, the fourth ring gear RG₄ enmeshed with the fifth planetary gear P₅, and the fourth carrier C₄ rotatably supporting the fifth planetary gear P₅ and connected with the output shaft. The fourth sun gear S₄ is locked to the gear casing when the third brake is actuated and a fourth brake B₄ is disposed so as to be capable of locking the fourth ring gear RG₄ to the gear casing.

Within the sixth embodiment, the radial ratios within each speed range which are calculated from the formula described in conjunction with the descriptiton of the first embodiment are I₁ = 0.419, I₂ = 0.500, I₃ = 0.355, and I₄ = 0.437. Table 6B shows the relationship between the operation of the clutches CL₁, CL₂, and CL₃ and the brakes B₁, B₂, B₃ and B₄ with respect to the reduction gear ratio within each speed range of the five forward speed ranges and the five reverse speed ranges, while Table 6C shows the relationship between the number of revolutions and the tangential forces of the various elements of the planetary gear sets within each speed range.

                  TABLE 6B                                                         ______________________________________                                                                                    Reduction                           CL1      CL2    CL3    B1   B2   B3   B4   gear ratio                          ______________________________________                                         F1    O                            O         3.82                              F2                  O              O         2.46                              F3           O                     O         1.49                              F4           O      O                        1.00                              F5           O           O                   0.67                              R1    O                                 O    -5.45                             R2    O                       O              -4.77                             R3                  O                   O    -2.35                             R4                  O         O              -2.00                             R5    O                  O                   -0.92                             ______________________________________                                    

                                      TABLE 6C                                     __________________________________________________________________________     B    X1                       X2                                               A    S1   C1   RG1  P1   P2   S2   C2   RG2  P3                                __________________________________________________________________________     F1 N 1.00 0.39 0.65 -0.93                                                                               0.93 0.65 0.39 0.26 -0.51                                W 0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0                               F2 N 1.55 0.60 1.00 -1.44                                                                               1.44 1.00 0.60 0.41 -0.79                                W 1.24 2.48 1.24 1.24 1.24 0.48 0.96 0.48 0.48                              F3 N 2.57 1.00 1.66 -2.38                                                                               2.38 1.66 1.00 0.67 -1.31                                W 0.41 0.83 0.41 0.41 0.41 0.83 1.65 0.83 0.83                              F4 N -1.39                                                                               1.00 0.0  3.64 -3.64                                                                               0.0  1.00 1.50 2.00                                 W 0.0  0.00 0.0  0.0  0.0  0.67 1.33 0.67 0.67                              R1 N 1.00 0.02 0.43 -1.49                                                                               1.49 0.43 0.02 -0.18                                                                               -0.82                                W 0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0                               R2 N 1.00 0.0  0.42 -1.52                                                                               1.52 0.42 0.00 -0.21                                                                               -0.84                                W 2.39 4.77 2.39 2.39 2.39 4.77 9.55 4.77 4.77                              R3 N 2.32 0.05 1.00 -3.46                                                                               3.46 1.00 0.05 -0.43                                                                               -1.90                                W 1.24 2.48 1.24 1.24 1.24 0.48 0.96 0.48 0.48                              R4 N 2.39 0.0  1.00 -3.64                                                                               3.64 1.00 0.0  -0.50                                                                               -2.00                                W 0.00 0.00 0.00 0.00 0.00 2.00 4.00 2.00 2.00                              R5 N 1.00 -0.72                                                                               0.0  -2.62                                                                               2.62 0.0  -0.72                                                                               -1.08                                                                               -1.44                                W 2.39 4.77 2.39 2.39 2.39 0.92 1.85 0.92 0.92                              __________________________________________________________________________             B X3                  X4                                               A         S3   C3   RG3  P4   S4   C4   RG4  P5                                __________________________________________________________________________     F1      N 1.00 0.26 0.0  -0.81                                                                               0.0  0.26 0.38 0.41                                      W 2.82 5.63 2.82 2.82 0.0  0.0  0.0  0.0                               F2      N 1.55 0.41 0.0  -1.26                                                                               0.0  0.41 0.58 0.63                                      W 1.46 2.93 1.46 1.46 0.0  0.0  0.0  0.0                               F3      N 2.57 0.67 0.0  -2.08                                                                               0.0  0.67 0.97 1.04                                      W 0.49 0.98 0.49 0.49 0.0  0.0  0.0  0.0                               F4      N -1.39                                                                               1.50 2.52 3.18 2.52 1.50 1.05 -1.59                                     W 0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0                               R1      N 1.00 -0.18                                                                               -0.60                                                                               -1.30                                                                               -0.60                                                                               -0.18                                                                               0.0  0.65                                      W 2.82 5.63 2.82 2.82 6.45 12.89                                                                               6.45 6.45                              R2      N 1.00 -0.21                                                                               -0.64                                                                               -1.33                                                                               -0.64                                                                               -0.21                                                                               -0.02                                                                               0.67                                      W 0.0  0.00 0.0  0.0  0.0  0.0  0.0  0.0                               R3      N 2.32 -0.43                                                                               -1.40                                                                               -3.02                                                                               -1.40                                                                               -0.43                                                                               0.0  1.51                                      W 1.46 2.93 1.46 1.46 3.35 6.70 3.35 3.35                              R4      N 2.39 -0.50                                                                               -1.52                                                                               -3.18                                                                               -1.52                                                                               -0.50                                                                               -0.05                                                                               1.59                                      W 0.00 0.00 0.00 0.00 0.00 0.0  0.0  0.0                               R5      N 1.00 -1.08                                                                               -1.82                                                                               -2.29                                                                               -1.82                                                                               -1.08                                                                               -0.76                                                                               1.15                                      W 0.00 0.00 0.00 0.00 0.00 0.0  0.0  0.0                               __________________________________________________________________________

Continuing further and with particular reference to FIG. 7A, a seventh embodiment of the present invention is disclosed wherein the structure thereof is similar to that of the first embodiment, the fourth planetary gear set X₄ of the single pinion type being disposed behind the third planetary gear set X₃ and comprising the fourth sun gear S₄, the fifth planetary gear P₅ engaged with the fourth sun gear S₄, the fourth ring gear RG₄ enmeshed with the fifth planetary gear P₅ and connected with the third ring gear RG₃, and the fourth carrier C₄ rotatably supporting the fifth planetary gear P₅ and connected with the third carrier C₃. The fourth ring gear RG₄ is locked to the gear casing when the third brake B₃ is actuated and a fourth brake B₄ is disposed so as to be capable of locking the fourth sun gear S₄ to the gear casing.

Within the seventh embodiment, the radial ratios within each speed range, which are calculated from the formula described in conjunction with the description of the first embodiment are I₁ = 0.419, I₂ = 0.500, I₃ = 0.355, and I₄ = 0.437. Table 7B shows the relationship between the operation of the clutches CL₁, CL₂ and CL₃ and the brakes B₁, B₂, B₃ and B₄ with respect to the reduction gear ratio within each speed range of the six forward speed ranges and the four reverse speed ranges, while Table 7C shows the relationship between the number of revolutions and the tangential forces of the various elements of the planetary gear sets within each speed range.

                  TABLE 7B                                                         ______________________________________                                                                                    Reduction                           CL1      CL2    CL3    B1   B2   B3   B4   gear ratio                          ______________________________________                                         F1    O                            O         3.82                              F2                  O              O         2.46                              F3           O                     O         1.49                              F4           O      O                        1.00                              F5           O                          O    0.73                              F6           O           O                   0.67                              R1    O                       O              -4.77                             R2                  O         O              -2.00                             R3    O                  O                   -0.92                             R4    O                                 O    -0.58                             ______________________________________                                    

                                      TABLE 7C                                     __________________________________________________________________________     B    X1                       X2                                               A    S1   C1   RG1  P1   P2   S2   C2   RG2  P3                                __________________________________________________________________________     F1 N 1.00 0.39 0.65 -0.93                                                                               0.93 0.65 0.39 0.26 -0.51                                W 0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0                               F2 N 1.55 0.60 1.00 -1.44                                                                               1.44 1.00 0.60 0.41 -0.79                                W 1.24 2.48 1.24 1.24 1.24 0.48 0.96 0.48 0.48                              F3 N 2.57 1.00 1.66 -2.38                                                                               2.38 1.66 1.00 0.67 -1.31                                W 0.41 0.83 0.41 0.41 0.41 0.83 1.65 0.83 0.83                              F4 N -0.80                                                                               1.00 0.24 2.75 -2.75                                                                               0.24 1.00 1.38 1.51                                 W 0.41 0.83 0.41 0.41 0.41 0.83 1.65 0.83 0.83                              F5 N -1.39                                                                               1.00 0.0  3.64 -3.64                                                                               0.0  1.00 1.50 2.00                                 W 0.0  0.0  0.0  0.0  0.0  0.67 1.33 0.67 0.67                              R1 N 1.00 0.0  0.42 -1.52                                                                               1.52 0.42 0.00 -0.21                                                                               -0.84                                W 2.39 4.77 2.39 2.39 2.39 4.77 9.55 4.77 4.77                              R2 N 2.39 0.0  1.00 -3.64                                                                               3.64 1.00 0.0  -0.50                                                                               -2.00                                W 0.00 0.00 0.00 0.00 0.00 2.00 4.00 2.00 2.00                              R3 N 1.00 -0.72                                                                               0.0  -2.62                                                                               2.62 0.0  -0.72                                                                               -1.08                                                                               -1.44                                W 2.39 4.77 2.39 2.39 2.39 0.92 1.85 0.92 0.92                              R4 N 1.00 -1.24                                                                               -0.30                                                                               -3.42                                                                               3.42 -0.30                                                                               -1.24                                                                               -1.71                                                                               -1.88                                W 0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0                               __________________________________________________________________________             B X3                  X4                                               A         S3   C3   RG3  P4   S4   C4   RG4  P5                                __________________________________________________________________________     F1      N 1.00 0.26 0.0  -0.81                                                                               0.73 0.26 0.0  -1.20                                     W 2.82 5.63 2.82 2.82 0.0  0.0  0.0  0.0                               F2      N 1.55 0.41 0.0  -1.26                                                                               1.13 0.41 0.0  -1.85                                     W 1.46 2.93 1.46 1.46 0.0  0.0  0.0  0.0                               F3      N 2.57 0.67 0.0  -2.08                                                                               1.87 0.67 0.0  -3.07                                     W 0.49 0.98 0.49 0.49 0.0  0.0  0.0  0.0                               F4      N -0.80                                                                               1.38 2.15 2.40 0.0  1.38 2.15 3.54                                      W 0.49 0.98 0.49 0.49 0.49 0.98 0.49 0.49                              F5      N -1.39                                                                               1.50 2.52 3.18 -0.32                                                                               1.50 2.52 4.68                                      W 0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0                               R1      N 1.00 -0.21                                                                               -0.64                                                                               -1.33                                                                               0.55 -0.21                                                                               -0.64                                                                               -1.96                                     W 0.0  0.00 0.0  0.0  0.0  0.0  0.0  0.0                               R2      N 2.39 -0.50                                                                               -1.52                                                                               -3.18                                                                               1.32 -0.50                                                                               -1.52                                                                               -4.68                                     W 0.00 0.00 0.00 0.00 0.0  0.0  0.0  0.0                               R3      N 1.00 -1.08                                                                               -1.82                                                                               -2.29                                                                               0.23 -1.08                                                                               -1.82                                                                               -3.37                                     W 0.00 0.00 0.00 0.00 0.0  0.0  0.0  0.0                               R4      N 1.00 -1.71                                                                               -2.68                                                                               -2.99                                                                               0.0  -1.71                                                                               -2.68                                                                               -4.40                                     W 2.82 5.63 2.82 2.82 2.82 5.63 2.82 2.82                              __________________________________________________________________________

Referring now to FIG. 8A, an eighth embodiment of the present invention is disclosed as comprising a first planetary gear set X₁ of the double pinion type, a second planetary gear set X₂ of the single-pinion type, a third planetary gear set X₃ and a fourth planetary gear set X₄ serially interposed between the input shaft and the output shaft, the first planetary gear set X₁ including a first sun gear S₁, a first planetary gear P₁ engaged with the first sun gear S₁, a second planetary gear P₂ enmeshed with the first planetary gear P₁, a first ring gear RG₁ engaged with the second planetary gear P₂, and a first carrier C₁ rotatably supporting the first and second planetary gears P₁ and P₂, while the second planetary gear set X₂ includes a third planetary gear P₃ engaged with a second sun gear S₂ which is in turn engaged with the first ring gear RG₁, a second ring gear RG₂ enmeshed with the third planetary gear P₃, and a second carrier C₂ rotatably supporting the third planetary gear P₃ and connected with the first carrier C₁.

The third planetary gear set X₃ comprises a third sun gear S₃, a fourth planetary gear P₄ engaged with the third sun gear S₃, a third ring gear RG₃ enmeshed with the fourth planetary gear P₄, and a third carrier C₃ rotatably supporting the fourth planetary gear P₄ and connected with the second ring gear RG₂, while the fourth planetary gear set X₄ similarly comprises a fourth sun gear S₄, a fifth planetary gear P₅ engaged with the fourth sun gear S₄, a fourth ring gear RG₄ enmeshed with the fifth planetary gear P₅ and also connected with the third sun gear S₃, and a fourth carrier rotatably supporting the fifth planetary gear P₅ and connected with the third carrier C₃ as well as the output shaft.

A first clutch CL₁ is disposed so as to be capable of simultaneously coupling or uncoupling the first sun gear S₁, the third sun gear S₃, and the fourth ring gear RG₄ to or from the input shaft, while a second clutch CL₂ is similarly disposed so as to be capable of simultaneously coupling or uncoupling the first carrier C₁ and the second carrier C₂ to or from the input shaft, and a third clutch CL₃ is likewise disposed so as to be capable of simultaneously coupling or uncoupling the first ring gear RG₁ and the second sun gear S₂ to or from the input shaft. A first brake B₁ is also disposed so as to be capable of simultaneously locking the first and second carriers C₁ and C₂ to the gear casing while a second brake B₂ is disposed so as to be capable of locking the third ring gear RG₃ to the gear casing, and a third brake B₃ is disposed so as to be capable of locking the fourth sun gear S₄ to the gear casing.

Within the eighth embodiment, the radial ratios within each speed range, which are calculated from the formula described in conjunction within the description of the first embodiment are I₁ = 0.419, I₂ = 0.500, I₃ = 0.355, and I₄ = 0.562. Table 8B shows the relationship between the operation of the clutches CL₁, CL₂ and CL₃ and the brakes B₁, B₂, and B₃ with respect to the reduction gear ratio within each speed range of the five forward speed ranges and the one reverse speed range, while Table 8C shows the relationship between the numer of revolutions and the tangential forces of the various elements of the planetary gear sets within each speed range.

                  TABLE 8B                                                         ______________________________________                                                                                    Reduction                           CL1      CL2    CL3    B1   B2   B3   B4   gear ratio                          ______________________________________                                         F1    O                       O              3.82                              F2    O                            O         1.56                              F3                  O              O         1.29                              F4           O                     O         1.10                              F5           O      O                        1.00                              R1    O                  O                   -4.77                             ______________________________________                                    

                                      TABLE 8C                                     __________________________________________________________________________     B    X1                       X2                                               A    S1   C1   RG1  P1   P2   S2   C2   RG2  P3                                __________________________________________________________________________     F1 N 1.00 0.39 0.65 -0.93                                                                               0.93 0.65 0.39 0.26 -0.51                                W 0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0                               F2 N 1.00 0.70 0.83 -0.45                                                                               0.45 0.83 0.70 0.64 -0.25                                W 0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0                               F3 N 1.21 0.85 1.00 -0.55                                                                               0.55 1.00 0.85 0.77 -0.30                                W 1.24 2.48 1.24 1.24 1.24 0.48 0.96 0.48 0.48                              F4 N 1.42 1.00 1.18 -0.65                                                                               0.65 1.18 1.00 0.91 -0.35                                W 0.41 0.83 0.41 0.41 0.41 0.83 1.65 0.83 0.83                              R1 N 1.00 0.0  0.42 -1.52                                                                               1.52 0.42 0.00 -0.21                                                                               -0.84                                W 2.39 4.77 2.39 2.39 2.39 4.77 9.55 4.77 4.77                              __________________________________________________________________________             B X3                  X4                                               A         S3   C3   RG3  P4   S4   C4   RG4   P5                               __________________________________________________________________________     F1      N 1.00 0.26 0.0  -0.81                                                                               -1.05                                                                               0.26 1.00 3.37                                      W 2.82 5.63 2.82 2.82 0.0  0.0  0.0  0.0                               F2      N 1.00 0.64 0.51 -0.40                                                                               0.0  0.64 1.00 1.64                                      W 0.00 0.0  0.0  0.0  1.00 2.00 1.00 1.00                              F3      N 1.21 0.77 0.62 -0.48                                                                               0.0  0.77 1.21 1.99                                      W 0.00 0.0  0.0  0.0  0.52 1.04 0.52 0.52                              F4      N 1.42 0.91 0.73 -0.56                                                                               0.0  0.91 1.42 2.34                                      W 0.00 0.00 0.00 0.00 0.17 0.35 0.17 0.17                              R1      N 1.00 -0.21                                                                               -0.64                                                                               -1.33                                                                               -2.36                                                                               -0.21                                                                               1.00 5.52                                      W 0.00 0.00 0.0  0.0  0.0  0.0  0.0  0.0                               __________________________________________________________________________

Referring now to FIG. 9A, a ninth embodiment of the present invention is disclosed wherein the structure is similar to that of the first embodiment, the fourth planetary gear set X₄ of the single-pinion type being disposed behind the third planetary gear set X₃ and comprising a fourth sun gear S₄ connected with the third sun gear S₃, a fifth planetary gear P₅ engaged with the fourth sun gear S₄, a fourth ring gear RG₄ enmeshed with the fifth planetary gear P₅, and a fourth carrier C₄ rotatably supporting the fifth planetary gear P₅ and connected with the carrier C₃ as well as the output shaft, a fourth brake B₄ also being disposed so as to be capable of locking the fourth ring gear RG₄ to the gear casing.

Within the ninth embodiment, the radial ratios within each speed range, which are calculated from the formula described in conjunction within the description of the first embodiment are I₁ = 0.419, I₂ = 0.500, I₃ = 0.355, and I₄ = 0.280. Table 9B shows the relationship between the operation of the clutches CL₁, CL₂ and CL₃ and the brakes B₁, B₂, B₃ and B₄ with respect to the reduction gear ratio within each speed range of the eight forward speed ranges and the three reverse speed ranges, while Table 9C shows the relationship between the number of revolutions and the tangential forces of the various elements of the planetary gear sets within each speed range.

                  TABLE 9B                                                         ______________________________________                                                                                    Reduction                           CL1      CL2    CL3    B1   B2   B3   B4   gear ratio                          ______________________________________                                         F1    O                                 O    4.57                              F2    O                            O         3.82                              F3                  O                   O    2.86                              F4                  O              O         2.46                              F5           O                          O    1.62                              F6           O                     O         1.49                              F7           O      O                        1.00                              F8           O           O                   0.67                              R1    O                       O              -4.77                             R2                  O         O              -2.00                             R3    O                  O                   -0.92                             ______________________________________                                    

                                      TABLE 9C                                     __________________________________________________________________________     B    X1                       X2                                               A    S1   C1   RG1  P1   P2   S2   C2   RG2  P3                                __________________________________________________________________________     F1 N 1.00 0.35 0.62 -0.98                                                                               0.98 0.62 0.35 0.22 -0.54                                W 0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0                               F2 N 1.0  0.39 0.65 -0.93                                                                               0.93 0.65 0.39 0.26 -0.51                                W 0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0                               F3 N 1.60 0.57 1.00 -1.58                                                                               1.58 1.00 0.57 0.35 -0.87                                W 1.24 2.48 1.24 1.24 1.24 0.48 0.96 0.48 0.48                              F4 N 1.55 0.60 1.00 -1.44                                                                               1.44 1.00 0.60 0.41 -0.79                                W 1.24 2.48 1.24 1.24 1.24 0.48 0.96 0.48 0.48                              F5 N 2.82 1.00 1.76 -2.78                                                                               2.78 1.76 1.00 0.62 -1.53                                W 0.41 0.83 0.41 0.41 0.41 0.83 1.65 0.83 0.83                              F6 N 2.57 1.00 1.66 -2.38                                                                               2.38 1.66 1.00 0.67 -1.31                                W 0.41 0.83 0.41 0.41 0.41 0.83 1.65 0.83 0.83                              F7 N -1.39                                                                               1.00 0.0  3.64 -3.64                                                                               0.0  1.00 1.50 2.00                                 W 0.0  0.0  0.0  0.0  0.0  0.67 1.33 0.67 0.67                              R1 N 1.00 0.0  0.42 -1.52                                                                               1.52 0.42 0.00 -0.21                                                                               -0.84                                W 2.39 4.77 2.39 2.39 2.39 4.77 9.55 4.77 4.77                              R2 N 2.39 0.0  1.00 -3.64                                                                               3.64 1.00 0.0  -0.50                                                                               -2.00                                W 0.00 0.00 0.00 0.00 0.00 2.00 4.00 2.00 2.00                              R3 N 1.00 -0.72                                                                               0.0  -2.62                                                                               2.62 -0.00                                                                               -0.72                                                                               -1.08                                                                               -1.44                                W 2.39 4.77 2.39 2.39 2.39 0.92 1.85 0.92 0.92                              __________________________________________________________________________             B X3                  X4                                               A         S3   C3   RG3  P4   S4   C4   RG4  P5                                __________________________________________________________________________     F1      N 1.00 0.22 0.06 -0.86                                                                               1.00 0.22 0.0  -0.61                                     W 0.0  0.00 0.00 0.00 3.57 7.14 3.57 3.57                              F2      N 1.00 0.26 0.0  -0.81                                                                               1.00 0.26 0.06 -0.57                                     W 2.82 5.63 2.82 2.82 0.00 0.0  0.0  0.0                               F3      N 1.60 0.35 -0.09                                                                               -1.38                                                                               1.60 0.35 0.0  -0.97                                     W 0.00 0.00 0.00 0.00 1.86 3.71 1.86 1.86                              F4      N 1.55 0.41 0.0  -1.26                                                                               1.55 0.41 0.09 -0.89                                     W 1.46 2.93 1.46 1.46 0.00 0.0  0.0  0.0                               F5      N 2.82 0.62 -0.17                                                                               -2.43                                                                               2.82 0.62 0.0  -1.72                                     W 0.00 0.0  0.0  0.0  0.62 1.24 0.62 0.62                              F6      N 2.57 0.67 0.0  -2.08                                                                               2.57 0.67 0.14 -1.47                                     W 0.49 0.98 0.49 0.49 0.00 0.0  0.0  0.0                               F7      N -1.39                                                                               1.50 2.52 3.18 -1.39                                                                               1.50 2.31 2.25                                      W 0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0                               R1      N 1.00 -0.21                                                                               -0.64                                                                               -1.33                                                                               1.00 -0.21                                                                               -0.55                                                                               -0.94                                     W 0.0  0.00 0.0  0.0  0.0  0.0  0.0  0.0                               R2      N 2.39 -0.50                                                                               -1.52                                                                               -3.18                                                                               2.39 -0.50                                                                               -1.31                                                                               -2.25                                     W 0.00 0.00 0.00 0.00 0.0  0.0  0.0  0.0                               R3      N 1.00 -1.08                                                                               -1.82                                                                               -2.29                                                                               1.00 -1.08                                                                               -1.66                                                                               -1.62                                     W 0.00 0.00 0.00 0.00 0.0  0.0  0.0  0.0                               __________________________________________________________________________

Thus, it is apparent that the speed change gear system of the present invention has important advantages over the known prior art systems in that speed change shifts through at least four speed ranges for forward drive can be attained by utilizing three basic planetary gear sets.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is to be understood therefore that within the scope of the appended claims the present invention may be practiced otherwise than as specifically described herein. 

What is claimed as new and desired to be secured by Letters Patent of the United States is:
 1. A speed change gear system comprising:an input shaft; a first sun gear; a first planetary gear engaged with said first sun gear; a second planetary gear engaged with said first planetary gear; a first ring gear engaged with said second planetary gear; a first carrier rotatably supporting said first and second planetary gears; a second sun gear engaged with said first ring gear; a third planetary gear engaged with said second sun gear; a second ring gear engaged with said third planetary gear; a second carrier rotatably supporting said third planetary gear and engaged with said first carrier; a third sun gear engaged with said first sun gear; a fourth planetary gear engaged with said third sun gear; a third ring gear engaged with said fourth planetary gear; a third carrier rotatably supporting said fourth planetary gear and engaged with said second ring gear; an output shaft engaged with said third carrier; a first clutch being capable of coupling or uncoupling simultaneously said first and third sun gears to or from said input shaft; a second clutch being capable of coupling or uncoupling simultaneously said first and second carriers to or from said input shaft; a third clutch being capable of coupling or uncoupling simultaneously said first ring gear and said second sun gear to or from said input shaft; a first brake being capable of locking simultaneously said first ring gear and said second sun gear to a gear casing; a second brake being capable of locking simultaneously said first and second carriers to said gear casing; and a third brake being capable of locking said third ring gear to said gear casing.
 2. A speed change gear system as set forth in claim 1 wherein said first brake is removed.
 3. A speed change gear system as set forth in claim 1 wherein said first clutch is removed. 